Microtomes of this kind are known from the existing art, for example from DE 103 52 578 B3, and are used predominantly for the production of thin paraffin sections in the fields of biology, medicine, and industrial research. The samples and preparations to be investigated are usually embedded in paraffin, in a preceding preparation process, into a specimen holding device, for example a carrier basket. A drive device that, by means of a relative motion, guides the sample, located in the specimen holding device, over a knife arranged on the microtome is provided for sectioning. The knife is generally horizontally displaceable in a knife holding device, and can be clamped in at an adjustable angle in defined fashion.
In so-called rotary microtomes, the drive device implements both the movement of the knife holding device in adjustable micrometer steps (referred to as horizontal advance) and the vertical sectioning motion, which is usually generated by a crank mechanism driven by a handwheel.
A trimming function can be provided in order to produce an optimum section surface. For this, the knife holding device can be manually directed onto the vertically movable specimen holding apparatus for first sectioning operations, via a trimming lever, in steps that are large as compared with the actual section thickness. Unusable sectioning waste occurs in this operation, and accumulates in a section collection pan of the microtome.
The samples to be investigated are often contaminated or bacterially infected biological material with which paraffin from the preparation process can be mixed. Even during ordinary sectioning of the samples with the microtome, fine sectioning waste unavoidably occurs; this drops down from the microtome knife and becomes deposited on portions of the microtome located therebelow, for example portions of its housing, in particular also in open gaps and especially in the section collection pan.
Because of the very complicated motion sequence, a complex mechanism is necessary on and in the microtome. Openings into the interior of the microtome, which are often covered with movable sliders, unavoidably remain at movement interfaces. Small slits, gaps, and openings in the microtome housing likewise occur, as a consequence of manufacture, in the vicinity of the aforesaid functional regions.
To prevent infection due to the contaminated sectioning waste, operating personnel are forced to intensively clean and disinfect the microtome and, in particular, the operating elements of the functional regions at relative short time intervals.
The section collection pan is particularly affected, since both the sectioning waste from trimming sections and the thin sections of contaminated samples that drop down build up in it. Large adhering sectioning waste fragments that are firmly in contact with the surface because of adhesion present a particular cleaning problem.